贴片机贴装5630速度:Eclipse 运行连接数据库为什么会报错

package com.szwdb;

import java.sql.*;

public class DBtest
{
String baseurl="jdbc:microsoft:sqlserver://localhost:1433;DatabaseName=";
String sql="select * from use_info";

DBtest(String data)
{ String url=baseurl+data;
try{
System.out.println("正在连接数据库.....");
Class.forName("com.microsoft.jdbc.sqlserver.SQLServerDriver");
Connection conn=DriverManager.getConnection(url,"sa","sa");
System.out.println("数据库连接成功！！！");
Statement st=conn.createStatement();
ResultSet rs=st.executeQuery(sql);
System.out.println("数据集获取成功！！！");

rs.close();
st.close();
conn.close();
}
catch(SQLException e){
e.printStackTrace();
}
catch(Exception se){
se.printStackTrace();
}
}

public static void main (String[] args)
{
new DBtest("book");
}
}

/***************为什么会报这样的错，我已经加入了3个jar包，msbase.jar,mmsalserver.jar,msutil.jar***********************************/
正在连接数据库.....
java.sql.SQLException: [Microsoft][SQLServer 2000 Driver for JDBC]Error establishing socket.
at com.microsoft.jdbc.base.BaseExceptions.createException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.base.BaseExceptions.getException(Unknown Source)
at com.microsoft.jdbc.sqlserver.tds.TDSConnection.<init>(Unknown Source)
at com.microsoft.jdbc.sqlserver.SQLServerImplConnection.open(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.getNewImplConnection(Unknown Source)
at com.microsoft.jdbc.base.BaseConnection.open(Unknown Source)
at com.microsoft.jdbc.base.BaseDriver.connect(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at java.sql.DriverManager.getConnection(Unknown Source)
at com.szwdb.DBtest.<init>(DBtest.java:19)
at com.szwdb.DBtest.main(DBtest.java:42)